I believe there is a Vinaya rule against monks and nuns officiating over a wedding ceremony. Due to this, there is no official form of marriage in Buddhism, afaik. However there are some Suttas that imply monogamy as the best form. The Buddha apparently never spoke out against the polygamy of some of the kings.

David N. Snyder wrote:I believe there is a Vinaya rule against monks and nuns officiating over a wedding ceremony.

It’s not a rule as such, but rather a disputed modern application of the fifth saṅghādisesa rule — the prohibition against acting as a go-between between a man and woman for the sake of effecting a marriage, betrothal or temporary liaison. Some hold that officiating at a marriage would amount to breach of this rule. However, this is a minority view (I’ve only ever heard it from some of the monks at Wat Pa Nanachat, based apparently on an old article by Ajahn Brahmavaṃso) and it doesn’t seem correct to me, nor to any of the Thai or Burmese Vinaya scholars with whom I’ve raised the subject. I think the most that can be claimed is that officiating at weddings is not among the traditional rôles of a bhikkhu. Instead, the usual practice is to leave it to the secular authorities to perform the wedding and then bless the couple with paritta-chanting afterwards.

But to come back to the fifth saṅghādisesa, as far as the spirit of this rule is concerned, it’s clear that what is prohibited are such acts as matchmaking and procuring, but this is not really what a wedding officiant is doing. At a wedding the ‘match’ is already a fait accompli and the officiant does no more than ratify it. On the other hand, to conform to the letter of Vinaya a bhikkhu officiating at a wedding would need to ensure that the liturgy was worded in a way that didn’t entail any of the three component acts involved in matchmaking: accepting the request of one party to convey a proposal (paṭiggaṇhanaṃ), enquiring into the response of the other party (vīmaṃsanaṃ), or reporting the response back to the first party (paccāharaṇaṃ).

I am glad for Ven. Dhammanando's opinion, above. It seems to me that a part of the cultivation of the lay Sangha would be having Bhikkhus/Bhikkhunis involved in important events in the lives of lay people. Certainly, monks are there for the questions and answers, pindabaht, Dhamma talks, the house blessings, are there for the funerals...so it would seem to be a good thing to have these monks as celebrants for one of the most positive events for many families. It would be a shame for a monk to turn down a couple that he/she had counseled and taught, based on a Vinaya interpretation that is subject to ambiguity or a more compassionate view. I wonder if the engaging Ajahn Brahm, who must get asked every week to celebrate a marriage from members of his Sangha, still holds to his early position as he stated in his brief.

robertk wrote:of course Kings and the rich had many wives in the Buddhas day. The average man seemed to have only one wife.

There may be another difference, in relation to status. In comparison, sultans of the Osman dynasty were not supposed to marry at all; they indeed had a harem of concubines with whom they were supposed to produce offspring for the purposes of the ruling dynasty and the continuance thereof; but formally, they could not marry and have no legal wife or wives. Whereas commoners could marry one wife.Maybe this kind of system was in place in other parts of the world as well.

BuddhaSoup wrote:I wonder if the engaging Ajahn Brahm, who must get asked every week to celebrate a marriage from members of his Sangha, still holds to his early position as he stated in his brief.

Actually since writing I've learned that I misidentified the ajahn. The view was actually set forth in The Heritage of the Sangha, an unpublished Vinaya treatise by the Canadian Wat Pa Nanachat monk Ven. Thiradhammo. Thiradhammo's opinion was later cited with approval by the English monk Ven. Ariyesako in his Bhikkhus' Rules - A Guide for Laypeople.

As for Ajahn Brahmavaṃso, I don't know what his views are on bhikkhus' officiating at heterosexual marriages, but he is on record as saying that he would be happy to do so at homosexual ones.

Whether there is a rule prohibiting it I don't see why Bhikkhus should be expected to perform the role of marriage celebrant. I think the expectation arises because "religious prefoessionals" of other religions do it, but it seems inappropriate to me that someone who has renounced marriage should be expected to have anything to do with the marriages of others.

The custom in asia is that the married couple invite Bhikkhus to their home on the morning of the wedding and offer them a meal, this seems like an appropriate way for Bhikkus to be involved, in Thailand marriages are often conducted by hindu priests or town officials.

As for polygamy if all parties are consenting and nobody is hurt by the arrangement then I'm not sure there is anything prohibiting it except the laws of the country.

“Peace is within oneself to be found in the same place as agitation and suffering. It is not found in a forest or on a hilltop, nor is it given by a teacher. Where you experience suffering, you can also find freedom from suffering. Trying to run away from suffering is actually to run toward it.” ― Ajahn Chah

Goofaholix wrote:As for polygamy if all parties are consenting and nobody is hurt by the arrangement then I'm not sure there is anything prohibiting it except the laws of the country.

Personally, I can't think of many things that are as Dukkha inducing than a polygamous relationship.

“No lists of things to be done. The day providential to itself. The hour. There is no later. This is later. All things of grace and beauty such that one holds them to one's heart have a common provenance in pain. Their birth in grief and ashes.” - Cormac McCarthy, The Road

Learn this from the waters:in mountain clefts and chasms,loud gush the streamlets,but great rivers flow silently.- Sutta Nipata 3.725

Here are some interesting modern Theravadan monastic takes on polygamy:

Knowing moderation in sexual relations: In the household life there exists the family structure, based around husband and wife. Know who your husband or wife is, know moderation, know the proper bounds of sexual activity. Some people don't know the limits. One husband or wife isn't enough, they have to have a second or third. The way I see it, you can't consume even one partner completely, so to have two or three is just plain indulgence.

(Ajahn Chah)

I knew a rich man who had many wives. One day one of his minor wives came to the house and had an argument with his major wife. He tried to persuade them to get on together and pacify the argument, but to no avail - they continued to argue amongst themselves. Having many wives he also had many children, so he would spend time moving from household to household. He never found any happiness in any of them, despite his immense wealth. I felt a sadness and weariness with the situation of the world.